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以等摩尔的硝酸钠和硝酸钾作为反应介质,氢氧化钠作为碱化剂,采用熔盐法制备了GdVO4:Eu3+纳米晶。利用X射线衍射(XRD)仪、傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)、荧光光谱(PL)和荧光寿命(Lifetime)等手段对产物的相态、结晶度、结构、形貌和发光性能等进行了表征与研究。X射线衍射结果表明,产物在250°C时开始结晶,400°C时结晶完全,控制反应体系碱度和温度可获得纯四方相GdVO4:Eu3+晶体。透射电镜观察结果显示,产物为粒径20 nm左右的立方形颗粒,分散良好,形貌均一。依据XRD数据计算结果表明,GdVO4:Eu3+纳米晶的晶胞参数和晶胞体积相对于体相材料均有所减小,归因于纳米晶表面大量悬键的存在,并通过FT-IR得到验证。315 nm波长光的激发下,GdVO4:Eu3+纳米晶呈现Eu3+的特征发射光谱,表明了能量由VO43-向Eu3+的传递。发射强度和荧光寿命研究表明,Eu3+的最佳掺杂浓度为5%(摩尔分数)。
GdVO4: Eu3 + nanocrystals were prepared by molten salt method using equimolar sodium nitrate and potassium nitrate as reaction medium and sodium hydroxide as alkalizing agent. The phase state, crystallinity, crystallinity and crystallinity of the product were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), fluorescence spectroscopy (PL) and fluorescence lifetime (Lifetime) Structure, morphology and luminescent properties were characterized and studied. X-ray diffraction results show that the product begins to crystallize at 250 ° C and crystallizes completely at 400 ° C. Pure tetragonal phase GdVO4: Eu3 + crystals can be obtained by controlling the basicity and temperature of the reaction system. Transmission electron microscopy showed that the product was cubic particles with a particle size of about 20 nm, with good dispersion and uniform morphology. The calculation results of XRD data show that the lattice parameters and the unit cell volume of GdVO4: Eu3 + nanocrystals decrease with respect to the bulk materials due to the existence of a large number of dangling bonds on the nanocrystal surface and are verified by FT-IR . Excited by 315 nm light, GdVO4: Eu3 + nanocrystals exhibit the characteristic emission spectra of Eu3 +, indicating the transfer of energy from VO43- to Eu3 +. Emission intensity and fluorescence lifetime studies have shown that Eu3 + the best doping concentration of 5% (mole fraction).